applied sciences Article Optimal Dispatch Strategy of Virtual Power Plant for Day-Ahead Market Framework Poushali Pal 1 , Parvathy Ayalur Krishnamoorthy 1, Devabalaji Kaliaperumal Rukmani 1 , S. Joseph Antony 2, Simon Ocheme 2, Umashankar Subramanian 3 , Rajvikram Madurai Elavarasan 4,* , Narottam Das 5,6,* and Hany M. Hasanien 7 1 Department of Electrical and Electronics Engineering, Hindustan Institute of Technology and Science, No. 1, OMR Road, Chennai 603103, India; [email protected] (P.P.); [email protected] (P.A.K.); [email protected] (D.K.R.) 2 School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, UK; [email protected] (S.J.A.); [email protected] (S.O.) 3 Renewable Energy Lab, Department of Communication and Networks, College of Engineering, Prince Sultan University, Riyadh 11586, Saudi Arabia; [email protected] 4 Clean and Resilient Energy Systems Laboratory (CARES), Texas A & M University, Galveston, TX 77553, USA 5 School of Engineering and Technology, Central Queensland University, Rockhampton, QLD 4701, Australia 6 Centre for Intelligent Systems, School of Engineering and Technology, Central Queensland University, Rockhampton, QLD 4701, Australia 7 Electrical Power and Machines Department, Faculty of Engineering, Ain Shams University, Cairo 11566, Egypt; [email protected] * Correspondence: [email protected] (R.M.E.); [email protected] (N.D.) Abstract: Renewable energy sources prevail as a clean energy source and their penetration in the Citation: Pal, P.; Krishnamoorthy, power sector is increasing day by day due to the growing concern for climate action. However, the P.A.; Rukmani, D.K.; Antony, S.J.; intermittent nature of the renewable energy based-power generation questions the grid security, Ocheme, S.; Subramanian, U.; especially when the utilized source is solar radiation or wind flow. The intermittency of the renewable Elavarasan, R.M.; Das, N.; Hasanien, generation can be met by the integration of distributed energy resources. The virtual power plant H.M. Optimal Dispatch Strategy of (VPP) is a new concept which aggregates the capacities of various distributed energy resources, Virtual Power Plant for Day-Ahead handles controllable and uncontrollable loads, integrates storage devices and empowers participation Market Framework. Appl. Sci. 2021, 11, 3814. https://doi.org/10.3390/ as an individual power plant in the electricity market. The VPP as an energy management system app11093814 (EMS) should optimally dispatch the power to its consumers. This research work is proposed to analyze the optimal scheduling of generation in VPP for the day-ahead market framework using Academic Editor: Nikolaos Paterakis the beetle antenna search (BAS) algorithm under various scenarios. A case study is considered for this analysis in which the constituting energy resources include a photovoltaic solar panel (PV), Received: 26 January 2021 micro-turbine (MT), wind turbine (WT), fuel cell (FC), battery energy storage system (BESS) and Accepted: 2 March 2021 controllable loads. The real-time hourly load curves are considered in this work. Three different Published: 23 April 2021 scenarios are considered for the optimal dispatch of generation in the VPP to analyze the performance of the proposed technique. The uncertainties of the solar irradiation and the wind speed are modeled Publisher’s Note: MDPI stays neutral using the beta distribution method and Weibull distribution method, respectively. The performance with regard to jurisdictional claims in of the proposed method is compared with other evolutionary algorithms such as particle swarm published maps and institutional affil- optimization (PSO) and the genetic algorithm (GA). Among these above-mentioned algorithms, the iations. proposed BAS algorithm shows the best scheduling with the minimum operating cost of generation. Keywords: distributed energy resources (DERs); virtual power plant (VPP); energy management system (EMS); day-ahead market; beetle antenna search (BAS) algorithm Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and 1. Introduction conditions of the Creative Commons Attribution (CC BY) license (https:// The scheduling problem of distributed energy resources is a major issue in power creativecommons.org/licenses/by/ systems due to different objectives and procedures, and its limitations. Microgrids and 4.0/). virtual power plants (VPPs) are two eminent solutions for the optimal scheduling problem. Appl. Sci. 2021, 11, 3814. https://doi.org/10.3390/app11093814 https://www.mdpi.com/journal/applsci Appl. Sci. 2021, 11, 3814 2 of 25 Various aspects of VPPs and the microgrid scheduling problem such as solving methods, modeling techniques and uncertainty were discussed in [1]. The VPP integrates various distributed energy resources (DERs), Energy Storage System (ESS), small conventional power plants and controllable loads, so the bidding strategy within the market is necessary to conduct analyses. The strategic bidding equilibrium of virtual power plants in a joint reg- ulation and energy market was analyzed. A bi-level mathematical program was developed for maximizing the profit as well as social welfare maximization of each producer. The bi-level problem was formulated as a mixed-integer linear programming model and the power transmission distribution factors (PTDF) were used for modeling the transmission constraints [2]. The power system can operate most efficiently by optimal energy manage- ment. Demand response can play an important role for managing the sources optimally. A detailed review was presented based on the different aggregation technologies of the VPP and developments of demand side resources [3]. The VPP integrates a wide variety of distributed generation resources such as photovoltaic, wind and hydro power plants and can enable the small sources to participate in the wholesale electricity market. The VPP operation can be maximized by optimizing the economic benefits of the system [4]. A fully distributed approach of the VPP was presented for maximizing the economic benefits subjected to line transmission limits, power balance constraints and the local constraints for the distributed energy resources. A distributed VPP dispatch algorithm was developed for this purpose, in which the centralized control system is not needed [5]. The integration of renewable generation such as photovoltaic and wind is highly volatile and leads to the problem of grid security. The control of the generation in a VPP pool leads to reconsidering the dynamic constraints, which makes the system more complex. A time domain simulation was presented for improving the power quality of the VPP, which consists of photovoltaic power, wind power and pumped storage integrated with an islanded grid including a thermal power plant [6]. The VPP aggregates several small-size generators which are situated close to the loads. The quality of power production by the VPP can be improved by optimizing the profit. A VPP model was considered which consists of two Distributed Generator (DGs) loads and a microgrid. The maximization of profit was formulated as a non-linear maximization problem with constraints. GAMS software was used to solve the optimization problem [7]. The VPP can operate with maximum efficiency when its generations are at the utmost condition. The small-scale wind turbine is of great interest in the VPP. To achieve the maximum energy from the wind turbine, two modeless methods were designed such as intelligent and non-linear strategies based on the HCS method. Fuzzy logic control (FLC) was used to implement intelligent Maximum Power Point Tracking (MPPT) due to its ability to cope with the problem related to the conventional methods [8]. The small-scale distributed energy resources can participate in the wholesale electricity market with the VPP concept. The correlated operation of several distributed energy resources implies surplus profit for the VPP. A profit-sharing scheme was developed for the combination of DERs. This scheme can be applied to the VPP dispatching center for reserve markets and energy trading [9]. Although a profit-sharing scheme of distributed energy resources was developed, the authors did not consider the constraints of the DG and energy storage system, which effects the generated power quality. A real-time control strategy was developed for ac- tive power dispatch among the units. The optimization problem was solved with the interior-point approach by considering the controllable DG capacity constraints to obtain the balance between demand and generation [10]. The security issues of the future energy supply and the concern about the environment’s health have led the research activities on alternative renewable energy systems. The VPP consists of renewable generation such as solar and wind, which are stochastic in nature. Hence, to maintain the grid security, these sources should be combined with dispatchable generation. An economic operation-based load-dispatching algorithm was developed which consists of a forecasting algorithm by the combination of the cascade-forward neural network, empirical mode decomposition Appl. Sci. 2021, 11, 3814 3 of 25 and linear model [11]. The main policy of European energy is to supply green energy in an efficient manner. Therefore, distributed generation technologies such as Renewable Energy Source (RES)-based generation with combined heat and power coupled to district